1. Field of the Invention
The invention relates to self-stabilizing walking platforms that can be reprogrammed and, more particularly, to a self-stabilizing quadruped walking platform that can be controlled in a fashion allowing flexible user programming and operation.
2. Description of the Related Art
There are numerous examples in the prior art of walking quadruped devises that try to walk in a fashion that is similar to four-legged animals. Many of these devices use twelve motors with three used in conjunction with each limb and a gyroscope. The first of these motors controls the motion of the hip joint of the limb, the second motor controls the upper leg joint of the limb, while the third and final motor of the limb controls the knee joint. All four limbs and the motors associated therewith are controlled by a separate CPU and servo for each motor which communicate with each other and the gyroscope and adjust the movement and timing of the limbs so that these devises can walk. These devices can walk in a forward direction, in a reverse direction, or turn, all as determined by the coordination of the CPU""s. As a result, such an apparatus can mimic some of the basic movements of a canine or other quadrupedal animal. However, prior art devices are still unsatisfactory for three reasons.
One problem is that these devices do not have enough stability that is incorporated into their structural elements to provide self-stabilization. In order to overcome this limitation, they rely on the communication and coordination of multiple CPU""s that are capable of handling at least thirty-five million instructions per second, servos, and a gyroscope to maintain balance by making sure that their center of balance does not fall outside of their stability envelope while they are walking. The large number of CPU""s with a high computing power, the gyroscope, and servos increase the overall cost of these devices significantly. This can be cost prohibitive in the robotics and toy fields where amateurs wish to have a walking device that can mimic the motion of animals but cannot afford to pay the price that is currently associated therewith. Accordingly, there exists a need for a walking apparatus that can maintain stability in a manner that does not require multiple CPU""s and is more cost effective than found in the prior art.
Another problem with these devises is that they lack the ability to alter the way they move because they are rigidly preprogrammed to act a certain way. This leaves these devices incapable of adapting to their environment and altering their response to stimuli and obstacles found therein. This can be disadvantageous in toy applications where the user may grow tired of having the apparatus behave in an identical fashion every time the apparatus is used. This may also be disadvantageous in robotics applications where the user may need the apparatus to move and act in different ways in order to achieve some desired result such as solving a problem or gaining access to a remote area. Accordingly, there exists a need for a walking apparatus that can alter its behavior in a manner that is consistent with the needs and desires of the user while also maintaining its ability to adapt to its environment.
A third problem with these prior art devices is that they do not provide adequate means for the user to control them. Typically, these devices employ RF remote controllers as the sole method by which the user can tell the apparatus how to move. These remote controllers often require the user to move a joystick in order to indicate to the CPU what direction the user wishes the apparatus to move. Although this method is satisfactory for simple movements in horizontal directions, it can be unwieldy if not impossible to use such a remote controller to effectuate complex three dimensional movement that may not even be ambulatory in nature. Like-wise, some devices use on board CPU""s solely for control of the apparatus which prevents the user from directly determining the movement of that apparatus. These types of control can be disadvantageous in toy and robotics applications where the user may wish to make the apparatus simulate unique and very precise movements in order to create some desired end result. Accordingly, there exists a further need for a walking apparatus that has a suitable means of control that can cause the apparatus to make precise three dimensional movements.
In accordance with the present invention, a walking apparatus is provided that includes the ability to maintain stability by itself, the ability to be reprogrammed, and the ability to reproduce precise three dimensional movements. The combination of these features render the apparatus more like animals and at a lower cost than those devices found in the prior art.
One embodiment of the invention that is capable of maintaining self-stabilization comprises at least one motor within the apparatus that has a drive shaft extending therefrom for powering the apparatus, two front legs that are in communication with the motor that also have a pair of weights attached thereto, two rear legs that are also in communication with the motor, and a separate weight that is positioned toward the front of the apparatus. As a result of the distribution of these weights, the center of balance of the apparatus is moved toward the front of the apparatus. Hence, as the apparatus walks and lifts a rear leg, the center of balance is maintained within the resulting triangular shaped stability envelope. Consequently, a described embodiment employs a single information processor with a relatively low computing power and an encoder to control the movement of the apparatus and no gyroscope unlike prior art devices which need multiple information processors with a high computing power to keep track of the movement of all the legs to make sure that the center of balance does not fall outside of the stability envelope. Furthermore, this embodiment may include at least one animation motor that is used by the apparatus to achieve non-ambulatory movement.
Another embodiment of the present invention that is capable of being reprogrammed includes a cartridge slot into which an intermediate flash cartridge can be inserted. This feature allows the user to download new programming which can alter the way the apparatus moves or behaves. Thus, the apparatus could for example act like a dog and then be reprogrammed to act like a cat. This feature solves the problem of the user getting tired of the apparatus exhibiting the same behavior repeatedly. In addition, games may be downloaded to the apparatus so that the user can play against the apparatus in games like tic, tac, toe. Finally, the cartridge slot can be used to download improvements and fix bugs concerning the programming of the apparatus. This embodiment is also capable of remote diagnostics so that someone other than the user who is more knowledgeable about the workings and programming of the apparatus can determine what is wrong with the apparatus and take the appropriate course of action.
Yet another embodiment of the present invention that is capable of reproducing precise three dimensional movements comprises an input apparatus which may be manipulated much as a puppeteer either manually or mechanically. The position of the legs as they are moved is detected by encoders that are located within the input apparatus and then is transmitted to the output apparatus whose information processor directs the legs of that apparatus to mimic the position of the legs of the input apparatus in real time. Alternatively, the puppeteer may choose to record the movements of the input apparatus via computer which is hard wired to the input apparatus. Then the movements and timing of the recording can be manipulated on the computer until the puppeteer is satisfied with the end result. Next, the altered program may be downloaded to the output apparatus via the intermediate flash cartridge that is inserted into the cartridge slot, which is part of the output apparatus, and executed just as any other program. These features provide a way to control the output apparatus so precisely that it can reproduce three dimensional movements that are not possible to execute using traditional methods of control such as a joystick remote control.
The various different embodiments that have been described may be powered electrically, chemically, by solar power, etc. to cause any of their motors to turn and move the apparatus. It is also readily apparent to those skilled in the art that these features can be applied to walking devises that have fewer and more than four legs as well. As can be seen, this invention provides a walking apparatus that can maintain self-stabilization, that can be reprogrammed, and that can reproduce precise three dimensional movements at a cost that is less than found in prior art devices.